Startup Tests Egg-Beater-Type Wind Turbine That Can Resist Typhoons On Okinawa

Japan Times - Chisaki Watanabe

Challenergy Inc.'s wind turbine is intended to be more resilient to wind than traditional machines that use large propellers. COURTESY OF CHALLENERGY INC.

With hurricanes threatening Florida and typhoons lashing Japan, a startup company working on the island of Okinawa is testing a wind turbine that could withstand winds that blow the blades off traditional machines.

Atsushi Shimizu BLOOMBERG

Backed by government grants and loans, Challenergy Inc., run by Atsushi Shimizu, is working to bring to market a machine that looks like an old-fashioned egg-beater, using rotating cylinders to generate electricity from the wind. His turbine, installed on Okinawa Island, is intended to be more resilient than traditional machines that are essentially large propellers.

His work taps into a need for wind turbines to cope with extreme conditions that scientists say could become more commonplace with global warming. Though typhoons regularly strike eastern China, the Korean Peninsula, Taiwan and Japan, the risk is that they may get stronger as ocean temperatures rise, researchers Wei Mei and Shang-Ping Xie wrote in Nature Geoscience in September. They found storms in Northern Asia have intensified as much as 15 percent in the last 37 years.
Traditional turbine designers have been “bent on keeping the propellers and just keep repeating really minor changes for improvement,” Shimizu, 37, said in an interview in Tokyo between trips to Okinawa. “I wanted to explore a different way after seeing propellers blown off by typhoons in summer and broken by gusts in winter.”
On average, about 11 typhoons a year come within 300 km (186 miles) of Japan, and three make landfall, according to the Meteorological Agency. Japan was hit with more typhoons than usual this season.
Shimizu hopes his design, a machine 7 meters (23 feet) high with three rotating cylinders, will prove resilient to such winds, doing away with the blades found on traditional turbines.
The turbine harnesses what’s known as the Magnus effect, where a sideways force is exerted on a spinning object. When the cylinders are spinning, the Magnus effect kicks into play, powering a generator as part of a process that’s yet to be found in any other commercialized product, Shimizu said. It’s meant to take advantage of wind blowing from different directions, offering better control of output in variable wind speeds.
It was the 2011 Fukushima nuclear disaster that prompted Shimizu to think about clean energy. He quit his job at Keyence Corp., where he researched factory automation machines, and founded Challenergy in October 2014 to pursue his turbine ideas.
Challenergy won the backing of the Japanese government, receiving a two-year grant from the New Energy and Industrial Technology Development Organization totaling about ¥55 million ($535,000). It also raised ¥4 million in crowd-funding and received loans from the government-backed Japan Finance Corp.
Shimizu’s turbine technology is “very challenging, but it is a technology from Japan like no other, while there are 300 makers for small turbines globally,” said Hisashi Yoshioka, director of the startup group for innovation promotion at NEDO.
Challenergy’s office is in the corner of a garage belonging to Hamano Products Co., a small metal fabrication company in Tokyo’s Sumida Ward. Hamano invited Challenergy to set up shop at their garage after Shimizu won a business plan contest presided over by a panel that included Hamano President Keiichi Hamano. The garage is also home to a startup that is developing a detachable battery-based device to turn a unicycle into a three-wheel device to carry heavy items.
The turbine is designed to withstand typhoons with wind speeds of 80 meters per second, Shimizu said, adding that it’s also suitable for mountains buffeted by turbulent winds.
“If the turbine can keep producing power when a typhoon hits, that means it can work any place,” he said.
While the prototype in Okinawa was assembled using the same material as is found in sewage pipes for the cylinders, Shimizu is looking at carbon fiber-reinforced plastic for future models. The company has also been negotiating with several venture capitalists, he said.
Propeller-type windmills are designed to stop operating when wind speeds exceed 25 meters per second, according to the website of the Japan Weather Association, which is supporting Challenergy’s Okinawa project by providing know-how on wind condition observations and by setting up a customized site for weather information and data.
“It appears to be an interesting design, which could potentially enable wind turbines to continuously generate wind electricity in strong winds,” said Yiyi Zhou, a wind analyst for Bloomberg New Energy Finance. “However, its technology viability still remains unproven at this stage without (a) sufficient track record.”
Japan’s wind power capacity, currently at 3 gigawatts, is forecast to increase to 10 gigawatts by 2030, according to the government. The Japan Wind Power Association says the country has the potential for 36 gigawatts by then.
Shimizu wants to have his machine working in time for the Olympic Games in Tokyo in 2020.
“I want to see the turbine at Olympic venues and I want it to replace the Olympic torch,” Shimizu said. “The torch emits carbon dioxide.”

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